OpenE2K/qemu-e2k
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nbd: fix max_discard/max_transfer_length

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nbd_co_discard calls nbd_client_session_co_discard which uses uint32_t
as the length in bytes of the data to discard due to the following
definition:

struct nbd_request {
    uint32_t magic;
    uint32_t type;
    uint64_t handle;
    uint64_t from;
    uint32_t len; <-- the length of data to be discarded, in bytes
} QEMU_PACKED;

Thus we should limit bl_max_discard to UINT32_MAX >> BDRV_SECTOR_BITS to
avoid overflow.

NBD read/write code uses the same structure for transfers. Fix
max_transfer_length accordingly.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Peter Lieven <pl@kamp.de>
CC: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Denis V. Lunev 2015-02-06 14:24:43 +03:00 committed by Kevin Wolf
parent 75af1f34cd
commit fa21e6faa6
1 changed files with 9 additions and 0 deletions
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9
block/nbd.c
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@ -301,6 +301,12 @@ static int nbd_co_flush(BlockDriverState *bs)
return nbd_client_session_co_flush(&s->client);
}
static void nbd_refresh_limits(BlockDriverState *bs, Error **errp)
{
bs->bl.max_discard = UINT32_MAX >> BDRV_SECTOR_BITS;
bs->bl.max_transfer_length = UINT32_MAX >> BDRV_SECTOR_BITS;
}
static int nbd_co_discard(BlockDriverState *bs, int64_t sector_num,
int nb_sectors)
{
@ -396,6 +402,7 @@ static BlockDriver bdrv_nbd = {
.bdrv_close = nbd_close,
.bdrv_co_flush_to_os = nbd_co_flush,
.bdrv_co_discard = nbd_co_discard,
.bdrv_refresh_limits = nbd_refresh_limits,
.bdrv_getlength = nbd_getlength,
.bdrv_detach_aio_context = nbd_detach_aio_context,
.bdrv_attach_aio_context = nbd_attach_aio_context,
@ -413,6 +420,7 @@ static BlockDriver bdrv_nbd_tcp = {
.bdrv_close = nbd_close,
.bdrv_co_flush_to_os = nbd_co_flush,
.bdrv_co_discard = nbd_co_discard,
.bdrv_refresh_limits = nbd_refresh_limits,
.bdrv_getlength = nbd_getlength,
.bdrv_detach_aio_context = nbd_detach_aio_context,
.bdrv_attach_aio_context = nbd_attach_aio_context,
@ -430,6 +438,7 @@ static BlockDriver bdrv_nbd_unix = {
.bdrv_close = nbd_close,
.bdrv_co_flush_to_os = nbd_co_flush,
.bdrv_co_discard = nbd_co_discard,
.bdrv_refresh_limits = nbd_refresh_limits,
.bdrv_getlength = nbd_getlength,
.bdrv_detach_aio_context = nbd_detach_aio_context,
.bdrv_attach_aio_context = nbd_attach_aio_context,